/Engine/Source/Runtime/Engine/Classes/Sound/SoundWave.h
Utility which returns imported PCM data and the parsed header for the file. Returns true if there was data, false if there wasn't.
bool GetImportedSoundWaveData ( [TArray](API\Runtime\Core\Containers\TArray)< uint8 > & OutRawPCMData, uint32 & OutSampleRate, uint16 & OutNumChannels ) const